automotive hvac!

[g6679]

In one case we are changing the charge quantity to achieve the targetted in cab temperature in the vehicle.
But high pressure tripping is starting , it means system is unbalanced.
what are the criterians which decide whether the system is properly balanced or not?

 

[coolingunit]

Dear g6679,

At higher charge quantity, more volume of condenser is occupied with liquid,which is reducing the heat transfer efficiency of condenser, hence high pressure is raising thereby high pressure switch tripp off the compressor.

System balancing is something different which related to capacity selection and delivery of each component used in the a/c system.

More info, please write your back ground like qualification, company in which you are working and more.

Regards,
Coolingunit.
India.

 

[g6679]

very very thanks Coolingunit for replying.
I am mechanical enginner working in one of the leading automobile manufacturers in India.
I am working in Automotive air conditioning field.
I agree with u that it is to do with system balancing, I tried very much to get some study material regarding system balancing but couldn't get it.
Do you know any site or any book giving details in this field?
also are there any tips or is there any check-list available any where by which we can find the optimum charge quantity for given system?
keep in touch.

 

[quark]

I would like to check the following things first before doing anything else.

1. Your system should be free from noncondensable gases. These gases will increase system pressure. (actually you should have no bubble vacuum in the system.

2. Clogged condenser.

3. Actual condensation temperature vs design condensation temperature.

 

[mdonner]

Adding refrigerant is usually done while watching system pressures in attached service manifold manometers.
This is done slowly, watching sight glass bubbles until they disappear, and watching compressor suction inlet to see it just starts toget wet but not freeze.
I want to suggest two alternatives:
- getting services from skilled refrigeration journeman.
- try to get hold on a good book.
I have the "Modern Refrigeration and Air Conditioning" by Althouse/Turnquist/Bracciano from Goodhat Willcox.
Capter 27 is devotet to Automobile AC.

 

[g6679]

Dear all,
is there any site or any manufacturer's site available for design guidelines or any sort of literature regarding Automotive air conditioning?
since this is very specific application of air conditioning, I am finding it very difficult to get the information related to things like,

How to balance the system?
What are the various ways of improving the performance of individual components in the system?
If some one amongst you is having information about this sight please give me details.

 

[mdonner]

Try this site:

http://www.delanet.com/~pparish/index.htm

 

[kstifle]

You can purchase the course "Design and Development of Automotive Air Conditioning Systems" by Al Kargilis, P.E. at the following web site:

http://www.vehicledevelopment.com/.

Kargilis is considered the "expert" in automotive A/C systems.

K. Stifle, P.E.